The document discusses the anaesthetic management of diabetes mellitus, including the types and diagnosis of diabetes, physiology of insulin, perioperative response to surgery and anesthesia, complications, and considerations for management related to cardiovascular disease, renal dysfunction, neuropathies, and different types of surgery. It provides guidance on pre-operative, intra-operative, and post-operative glucose monitoring and management through intravenous fluids, insulin administration, and glycemic control targets. Surgical procedures for both insulin-dependent and non-insulin dependent diabetes are outlined.
2. Diabetes mellitus
Diabetes mellitus is characterized by impairment of
carbohydrate metabolism caused by an absolute or
relative deficiency of insulin or insulin
responsiveness, which leads to hyperglycemia and
glycosuria.
The diagnosis is based on an elevated fasting
plasma glucose(140mg/dl or 7.8mmol/l or more) &
random blood glucose(200mg/dl or 11.1mmol/l or
more)
3. Physiology of insulin
Insulin Production
50 units/day controlled by plasma glucose level.
Functions:
↑Glucose & Potassium entry into cells
↑Glycogen, protein & fatty acid synthesis
↓Gluconeogenesis, glycogenolysis,ketogenesis,
lipolysis & protein catabolism
Insulin promotes anabolism
Insulin lack promotes catabolism.
4. Diagnosis(based on blood glucose level)
FBS 126 mg/dl or 7.0mmol/l
RBS 200mg/dl or 11.1mmol/l
TYPE:
4 Types:
Type I Absolute insulin deficiency secondary to
immune-mediated or idiopathic(IDDM)
Type II Adult onset secondary to resistance/relative
deficiency(NIDDM)
Type III Specific types of diabetes mellitus secondary to
genetic defects
Type IV Gestational
5. Perioperative Response to
Surgery and Anesthesia (I)
Neuroendocrine stress response with release of
counterregulatory hormones.
1. peripheral insulin resistance,
2. increased hepatic glucose production,
3. impaired insulin secretion,
4. fat and protein breakdown,
5. potential hyperglycemia and even ketosis
in some cases.
6. Perioperative Response to
Surgery and Anesthesia
Fasting and volume depletion contribute to metabolic
decompensation.
Type I DM: Diabetic ketoacidosis may develop in the
absence of severe hyperglycemia because of
inadequate insulin availability during a time
of increased demand
Type 2 DM: Hyperglycemic hyperosmolar nonketotic
states
Infection
Wound healing
Local and epidural anesthesia: minimal effect
8. Diabetic Ketoacidosis(DKA)
Insulin lack Catabolism of free fatty acid into ketone
bodies (Acetoacetic acid & β hydoxybutyrate) which are
weak acids.
Identified by: ↑ plasma lactate(Lactic acidosis)
No urine/ plasma ketone bodies.
Precipitating factor Infection, trauma etc.
C/F:
Tachypnoea (to compensate met. Acidosis)
Nausea, vomiting, abdominal pain- like acute abdomen
Changes in sensorial
9. Treatment:
Correction of hypovolumia:
Total 5-6 Liters of Normal saline
1-2 L in first hour followed by 200-500 ml/hr in
subsequent hrs
To add 5 % DA when blood glucose drops to 250 mg/
dL
Correction of Hyperglycemia & potassium
Target: To reduce sugar by 75-100 mg/dl/Hour
10 units of soluble Insulin I/V in first hour by syringe
pump
If no response- double the dose.
Sugar, K+ & ketone bodies to be measured hrly
10. Hyper osmolar Non Ketotic
Coma(HONC)
No ketone body formation due to some insulin
Main feature
*Hyperglycaemia diuresis dehydration
hyperosmolarity (< 360 mosm/L)
*Dehydration leads to renal failure, lactic acidosis &
intravascular thrombosis.
*Hyperosmolarity(>360mOsm/L) cerebral water
balance change in mental status & seizures
Treatment:
Fluid, Insulin & potassium.
11. Hypoglycaemia:
< 50 mg/ DL
Excess insulin relative to CHO intake
Brain depends on glucose for energy.
Light headness, Confusion, convulsion & permanent
Coma.
Systemic features due to catecholamine release.
e.g. diaphoresis, tachycardia & nervousness.
GA masks the features
Treatment:
I/V glucose. 1 ml of 25% glucose raises 1 mg/DL
12. Diabetes and Surgery
Surgery is a form of physical trauma
It results in catabolism, increased metabolic rate, increased fat
and protein breakdown, glucose intolerance and starvation.
In a diabetic patient, the pre existing metabolic disturbances
are exacerbated by surgery
The type of diabetes, amount of insulin dose, diet or oral
hypoglycaemic agents must be considered as this will change
the overall management plan
The risk of significant end-organ damage increases with the
duration of diabetes, although the quality of glucose control is
more important than the absolute time
13. Determinants of the management plan
for diabetic patient
1. Type of DM
2. Treatment, diet, oral antidiabetic drugs,
insulin
3. Metabolic status
4. Vascular status: cardiac, renal, cerebral
5. Surgery:
Type: emergency or elective
Minor or major procedure
Type of anesthesia
Post operative oral intake
14. Factors Adversely Affecting Diabetic
Control Perioperatively
Anxiety
Starvation
Anaesthetic drugs
Infection
Metabolic response to trauma
Diseases underlying need for surgery
Other drugs e.g. steroids
15. Perioperative consideration
Related To Anesthesia
Cardiovascular Disease
Renal dysfunction
Peripheral and autonomic
neuropathies
Orthopedic Cause
16. Cardiovascular Disease
↑risk: hypertension, coronary artery disease,
diastolic dysfunction, congestive heart
failure, peripheral vascular disease and
cerebrovascular disease, etc.
Diabetes is not a contraindication to β-
adrenergic blocker administration when such
therapy is indicated
17. Management
Most cardiac and antihypertensive drugs should be
continued throughout the preoperative period except,
aspirin, diuretics and anticoagulants
History to determine effort tolerance, clinical
examination for cardiac failure and an
electrocardiogram in all patients.
Echocardiography can help in assessing an ejection
fraction in borderline cases
18. Renal Disease
Renal dysfunction commonly develops
Angiotensin converting enzyme inhibitors: ↓albuminuria
and progression of renal dysfunction
Consider renal function when selecting medications
(avoiding potential nephrotoxic drugs) and modify
dosage
Management:
Urea and electrolyte determination.
Dipsticks urinalysis for proteinuria
19. Peripheral and autonomic
neuropathies
Neuropathy and vascular compromise: ↑risk
for ischemia in pressure point while
positioning diabetic patients
Autonomic neuropathy: ↓compensatory
cardiovascular response, ↑gastroparesis and
predispose pulmonary aspiration
Management
History of postural dizziness, post gustatory
sweating, nocturnal diarrhoea and impotence.
Careful documentation of peripheral
sensation
20. Orthopedic cause
Stiff joint syndrome:
chronic hyperglycemia->↑abnormal collagen cross-linking-
> decreased joint mobility
->Decreased mobility in the temporomandibular and
cervical spine joints. 30% cases of difficult intubation..
Management
Clinical assessment of neck extension, examination of
the small joints of the hand and a good evaluation of
the ease of intubation
21. Pre-operative Assessment
This is the most important step in the management of
the diabetic patient
Involves a thorough history and physical examination
Review prior anaesthetic records to determine whether
there were any difficulties with intubation or
anaesthetics
Lab investigations
blood glucose - K+
BUN - creatinine
ketones - proteinuria
HbA1c (to assess how well controlled diabetes is)
22. Aims of peri-operative
management
Avoid hypoglycaemia
Avoid excessive hyperglycaemia
Avoid loss of electrolytes (potassium,
magnesium and phosphate)
Prevent lipolysis and proteolysis
H. J. Robertshaw1 and G. M. Hall. Diabetes mellitus: anesthetic
management. Anaesthesia, 2006, 61, p1187–1190
23. Target glucose level
Intravenous insulin therapy during the
perioperative period, labor and delivery
Targets:
a. ICU patients < 110 mg/dL or
b. Non-ICU patients < 110 mg/dL preprandial,
< 180 mg/dL maximum
c. Labor and Delivery patients < 100 mg/dL
26. Pre-Operative Management
Admit as early as possible prior to surgery
Avoid long-acting glucose lowering agents
chlorpropamide –glibenclamide
ultralente insulin
Avoid metformin
Closely monitor blood glucose levels
2 hourly for Type 1
4 hourly for type 2
Test urine every 8 hours for ketone
Place first on morning operating list if possible
Aim for a blood glucose of 5-10mmol/L
27. Intra-operative management
Interval of blood glucose check: <2hrs
Target of blood glucose: <180mg/dL
Plasma K level: 4.0–4.5 mmol/L, check at least 24h
Modify blood glucose:
a. concurrently running separate infusions of insulin and glucose
b. infusion of glucose mixed with insulin (with or without added
potassium), ex: glucose-insulin-potassium solutions (the GIK
system, or ‘Albert regimen’)
ref: H. J. Robertshaw1 and G. M. Hall. Diabetes mellitus:
anesthetic management. Anaesthesia, 2006, 61, p1187–1190
28. On the day of surgery
It is preferable to take diabetic patients for surgery in
the morning as first case.
Normally the requirement of insulin is 0.3 U to
metabolize 1gm of glucose.
When FPG < 120 mg % no insulin is given except 5%
glucose.
When FPG 120- 160 mg % 5 % glucose with 5 units
soluble insulin.
For FPG 160- 200 mg % 5 % glucose with 8 U of soluble
insulin.
29. Surgical Management of Insulin
Dependant Diabetes Mellitus
Aim to keep blood glucose 5 to10mmol/L
Pre-operative
NBM for 6 hrs prior to surgery (4 hrs for clear fluids)
Anti aspiration prophylaxis
Initiate glucose/ potassium/ insulin regime after commencing NBM (check
K+ as well)
500ml 10% glucose solution with 20mmol K+ at 1ml.kg-1.hr-1
connected to Y piece with insulin syringe
Make up insulin syringe as 50 units insulin in 50 ml saline in a 50 ml
syringe pump and run through Y piece with 10% glucose at between 1 to
5 u hr-1 (1 – 5 ml).
Base on existing insulin regime
Use sliding scale e.g. 1 u hr-1 if BG between 5 to 10mmole/l
Hourly capillary glucose is measured until operation
30. Surgical Management of Insulin
Dependant Diabetes Mellitus
Intra-operative
Anaesthesia determined by patient physiology
and surgical requirements
Hourly glucose monitoring
keep between 5-10 mmol/L
Two hourly potassium monitoring
keep between 3.5-4.5 mmol/L
Set up additional IV for resuscitation fluids
31. Surgical Management of Insulin Dependant
Diabetes Mellitus
Post-operative
Continue Glucose/Potassium/Insulin regime until
patient can take orally
Oral medication with first meal
Allow for pain resulting in increased insulin
requirements
32. Surgical Management of Non Insulin Dependant
Diabetes Mellitus
Treat as insulin dependant if:
poorly controlled (blood glucose >10 mmo/L)
major surgery
Pre-operative
Biguanides must be stopped 48 hours before hand for fear of
lactic acidosis
NBM for 12 hours prior to operation
Intra-operative
Start i.v maintenance fluid
0.18% NaCl with glucose 4%
Hourly capillary glucose is measured until operation
33. Surgical Management of Non Insulin
Dependant Diabetes Mellitus
Hourly glucose monitoring
Aim to keep within 5-10mmol/L or 90-180mg/dl
if blood glucose >10 mmol/L, switch to treating as
insulin dependant
Post-operative
Restart oral hypoglycaemic with first meal
34. Type of surgery
Minor intermediate/major
Pt. controlled by diet no specific precautions measure blood glucose 4 hourly
,if>12mmol/l or 216mg/dl
start glucose-potassium-insulin
sliding scale regimen
pt controlled by oral Omit medication on morning Omit medication and monitor
hypoglycemic drug of operation and start when blood glucose 1-2 hourly; if
eating normally >12mmol/l start glucose-
potassium-insulin sliding scale
regimen
Pt controlled by insulin unless very minor procedure(omit insulin when nil by
mouth)give glucose-potassium-insulin sliding scale regimen during
surgery and until eating normally postoperatively.
35. GKI sliding scale regimen:
Glucose-potassium-insulin sliding scale: infuse 10%
glucose500ml + 10 mmol potassium chloride(KCl) at
100ml/hr .prepare a 50 ml syringe containing 50 units of
actrapid(short acting)insulin in 50 ml normal saline and
connect via a 3 way tap to a glucose infusion, adjust the rate
of the syringe driver according to the following sliding scale
Blood glucose(mmol/l) rate of syringe driver(ml/hr)
<5 switch off
5-7 1
7-10 2
10-20 3
>20 4
36.
37. Emergency surgery
In emergency surgery it is deal to use
intravenous insulin infusion.
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39. GLUCOSE, FLUID, AND
ELECTROLYTE MANAGEMENT
Intravenous fluids
1. Dextrose saline / normal saline is used if blood pressure
is low or normal.
2. If there is hypertension half normal saline or 5 %
dextrose is given.
3. For normal metabolism 50 gm glucose is required every
8 hours for energy and to avoid ketosis, to meet this
demand at least 1000 cc 5 % glucose every 8 h will be
required.
4. In situations requiring fluid restriction 10 % dextrose can
be infused instead of 5 % with double the dose of insulin.
40. GLUCOSE, FLUID, AND
ELECTROLYTE MANAGEMENT
5 g of glucose per hour for basal energy requirements and to
prevent hypoglycemia, ketosis, and protein breakdown during
surgery.
More glucose may be needed if conditions are very stressful.
1. Short procedures: 5% dextrose : 100 mL per hour
2. Longer procedures: 10% dextrose: 50 mL per hour
3. 20 or 50% through a central line if fluid restriction is critical.
41. GLUCOSE, FLUID, AND
ELECTROLYTE MANAGEMENT
Normal serum potassium level does not necessarily
reflect a normal total body potassium
concentration.
Potassium into cells: Insulin and epinephrine
Potassium out of cells: hyperosmolarity causes, acidosis.
DM patient with normal renal function and serum potassium
levels, 10 to 20 mEq per L of potassium should be added per
liter of dextrose-containing fluid.
More potassium is given if hypokalemia is present. In
patients with hyperkalemia, potassium is not given unless
the level falls into the normal range.
42. Practical aspects
1. Whatever is the pattern of infusion, the blood
sugar has to be checked every 1- 2 hours and
the flow rate is adjusted.
2. Intra and post operative potassium
monitoring is done and corrected
appropriately.
3. A few hours after surgery there will be
reduction in the insulin requirement as the
elevated counter hormones due to surgical
stress decline.
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43. Other Considerations with Anaesthesia in
Diabetic Patients
Usual intra-operative monitoring
record BP and pulse every 5 minutes
watch skin colour and temp
suspect hypoglycaemia if patient is cold and sweaty
give IV glucose
No contraindications to standard anaesthetic induction or
inhalational agents
If the patient is dehydrated then hypotension will occur and
i.v. fluids will be needed
44. Our aim
To make patients safe for surgery, for this we need
an understanding team work between the
surgeon, anesthesiologist and diabetologist.
When the patient is under anesthesia the ideal is
to have diabetic therapy supervised by a diabetic
team where available.
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